As the continuous development of video encoding techniques, intra-frame motion searching and compensating techniques are capable of effectively removing time redundancy of video contents, greatly improving the efficiency of encoding; motion information is obtained through motion estimation and is then transmitted to a decoder where a video image is predicted and reconstructed by means of a method of motion compensation. Intra-frame motion compensation prediction technique means performing motion compensation by using motion vectors obtained through search in a process of encoding and decoding, so as to realize corresponding encoding and decoding operations.
As an encoding and decoding method, a technique for derivable motion vectors on decoder becomes more and more familiar to people for its great contributions to the encoding efficiency, and its great values are recognized by people, while being accepted as an important candidate tool for future video encoding standard.
A method from among the conventional techniques for derivable motion vectors for acquiring motion information comprises: obtaining a motion vector through template matching. Specifically, assuming that the current block is a macro block in frame B, as shown in FIG. 1. First, a template TM is constructed around the current block by using reconstruction values, and then motion vectors MV0 and MV1 are obtained as the motion vectors of the current block by performing search matching using a template of the same shape as the template TM in a forward reference image (Ref List0) and a backward reference image (Ref List1) of the block, a predicted value of the current block is obtained at the same time, and a predicted residual decoding is performed on the predicted value.
In the implementation of the present invention, the inventor found that at least the following defects exist in the prior art: the encoder does not transmit the motion vector of a predicted value to the decoder, and the decoder needs to obtain, before restoring a current block, the motion vector of the current block by means of a motion search process which increases the complexity of the decoder.